Re: [PATCH v6 10/17] firmware: arm_scmi: Make polling mode optional

[Cristian Marussi <cristian.marussi@arm.com>]

On Thu, Jul 15, 2021 at 06:36:10PM +0200, Peter Hilber wrote:
> On 12.07.21 16:18, Cristian Marussi wrote:
> > Add a check for the presence of .poll_done transport operation so that
> > transports that do not need to support polling mode have no need to provide
> > a dummy .poll_done callback either and polling mode can be disabled in the
> > SCMI core for that tranport.
> > 
> > Signed-off-by: Cristian Marussi <cristian.marussi@arm.com>
> > ---
> >   drivers/firmware/arm_scmi/driver.c | 43 ++++++++++++++++++------------
> >   1 file changed, 26 insertions(+), 17 deletions(-)
> > 
> > diff --git a/drivers/firmware/arm_scmi/driver.c b/drivers/firmware/arm_scmi/driver.c
> > index a952b6527b8a..4183d25c9289 100644
> > --- a/drivers/firmware/arm_scmi/driver.c
> > +++ b/drivers/firmware/arm_scmi/driver.c
> > @@ -777,25 +777,34 @@ static int do_xfer(const struct scmi_protocol_handle *ph,
> >   	}
> >   	if (xfer->hdr.poll_completion) {
> > -		ktime_t stop = ktime_add_ns(ktime_get(), SCMI_MAX_POLL_TO_NS);
> > -
> > -		spin_until_cond(scmi_xfer_done_no_timeout(cinfo, xfer, stop));
> > -
> > -		if (ktime_before(ktime_get(), stop)) {
> > -			unsigned long flags;
> > -
> > -			/*
> > -			 * Do not fetch_response if an out-of-order delayed
> > -			 * response is being processed.
> > -			 */
> > -			spin_lock_irqsave(&xfer->lock, flags);
> > -			if (xfer->state == SCMI_XFER_SENT_OK) {
> > -				info->desc->ops->fetch_response(cinfo, xfer);
> > -				xfer->state = SCMI_XFER_RESP_OK;
> > +		if (info->desc->ops->poll_done) {
> > +			ktime_t stop = ktime_add_ns(ktime_get(),
> > +						    SCMI_MAX_POLL_TO_NS);
> > +
> > +			spin_until_cond(scmi_xfer_done_no_timeout(cinfo, xfer,
> > +								  stop));
> > +
> > +			if (ktime_before(ktime_get(), stop)) {
> > +				unsigned long flags;
> > +
> > +				/*
> > +				 * Do not fetch_response if an out-of-order delayed
> > +				 * response is being processed.
> > +				 */
> > +				spin_lock_irqsave(&xfer->lock, flags);
> > +				if (xfer->state == SCMI_XFER_SENT_OK) {
> > +					info->desc->ops->fetch_response(cinfo,
> > +									xfer);
> > +					xfer->state = SCMI_XFER_RESP_OK;
> > +				}
> > +				spin_unlock_irqrestore(&xfer->lock, flags);
> > +			} else {
> > +				ret = -ETIMEDOUT;
> >   			}
> > -			spin_unlock_irqrestore(&xfer->lock, flags);
> >   		} else {
> > -			ret = -ETIMEDOUT;
> > +			dev_warn_once(dev,
> > +				      "Polling mode is not supported by transport.\n");
> > +			ret = EINVAL;
> 
> s/EINVAL/-EINVAL

Ah. Right. I'll fix.

Thanks,
Cristian